I just bought a 01 Navigator with 130k miles... Been stting since 2016. I just replaced the fuel pump with a Delphi unit. I did not drop/clean the tank. I am getting 171/174. Something to note here is that the fuel gauge turns off/on.
At idle, bank 2 is very lean around +20 LTFT . At idle bank 1 is around +/- 5% for both LTFT/STFT.
On WOT, bank 2 is +/- 4% both both LTFT and STFT. At WOT, bank 1 leans out.
At cruising, they are both lean. If I let off the gas after WOT suddenly it sputters and backfires. Sometimes the fuel trims go to +50% after WOT/Cruising and letting off gas!!!
Something else to note is the Catalytic converters were taken off and you can see both O2 sensors under the truck (they are still screwed into the exhaust pipes).
Also, something else to note is that it only takes 5gal of gas at a time. I replaced the fuel filler neck, but did not touch the evap system lines. Would this be related?
I have never seen anything similar to this where the lean condition jumps b/w each bank based on the load..
Any ideas from anyone?
At idle, bank 2 is very lean around +20 LTFT . At idle bank 1 is around +/- 5% for both LTFT/STFT.
On WOT, bank 2 is +/- 4% both both LTFT and STFT. At WOT, bank 1 leans out.
At cruising, they are both lean. If I let off the gas after WOT suddenly it sputters and backfires. Sometimes the fuel trims go to +50% after WOT/Cruising and letting off gas!!!
Something else to note is the Catalytic converters were taken off and you can see both O2 sensors under the truck (they are still screwed into the exhaust pipes).
Also, something else to note is that it only takes 5gal of gas at a time. I replaced the fuel filler neck, but did not touch the evap system lines. Would this be related?
I have never seen anything similar to this where the lean condition jumps b/w each bank based on the load..
Any ideas from anyone?
